Optical scanner and image forming apparatus

Abstract

An optical scanner includes: a light reflecting section having light reflectivity; a movable plate which includes the light reflecting section and can be displaced; four link sections connected to the movable plate; and a supporting section supporting the four link sections. The four link sections are provided on an outer circumference of the movable plate at 90-degree intervals along a circumferential direction of the movable plate in a plan view. Each link section includes a turnable drive section, and a shaft section which connects the movable plate and the drive section. The shaft section is bent and deformed in a thickness direction of the movable plate by turning the drive section.

What is claimed is: 
     
       1. An optical scanner comprising:
 a light reflecting section; 
 a movable plate provided to the light reflecting section; 
 four link sections connected to the movable plate; and 
 a supporting section supporting the four link sections, 
 wherein each link section includes:
 a movable plate-side shaft section connected to the movable plate; 
 a stress alleviating section connected to the movable plate-side shaft section, the stress alleviating section having a pair of deformation sections and a non-deformable section provided between the pair of the deformation sections; 
 a drive section-side shaft section connected to the stress alleviating section; 
 a drive section connected to the drive section-side shaft section, and 
 a pair of shaft sections connected to the drive section and the supporting section, 
 
 wherein the non-deformable sections, the drive section-side shaft section, the pairs of the shaft sections and the drive sections are each formed of a first Si layer, a SiO 2  layer, and a second Si layer, and 
 wherein the movable plate-side shaft sections, the pairs of the deformation sections, and the pairs of the shaft sections are each formed of the second Si layer. 
 
     
     
       2. The optical scanner according to  claim 1 , wherein the four link sections are provided on an outer circumference of the movable plate at 90-degree intervals along a circumferential direction of the movable plate in an X-Y plane view. 
     
     
       3. An image forming apparatus comprising:
 a light source; and 
 an optical scanner according to  claim 2 . 
 
     
     
       4. The optical scanner according to  claim 1 , wherein, in each of the link sections, the non-deformable section extends in a direction parallel to an extending direction of the deformation sections, and is torsionally non-deformable when the movable plate is driven. 
     
     
       5. An image forming apparatus comprising:
 a light source; and 
 an optical scanner according to  claim 4 . 
 
     
     
       6. The optical scanner according to  claim 1 , further comprising:
 a permanent magnet provided to each of the drive sections, and 
 four coils, each of the four coils producing a magnetic field that acts on each of the permanent magnets. 
 
     
     
       7. The optical scanner according to  claim 6 , wherein the permanent magnets are each provided such that two poles face each other in a thickness direction of the movable plate, and each of the coils are provided so as to produce a magnetic field in a direction perpendicular to the thickness direction of the movable plate. 
     
     
       8. An image forming apparatus comprising:
 a light source; and 
 an optical scanner according to  claim 7 . 
 
     
     
       9. The optical scanner according to  claim 6 , wherein each of the permanent magnets penetrates each of the drive sections. 
     
     
       10. An image forming apparatus comprising:
 a light source; and 
 an optical scanner according to  claim 9 . 
 
     
     
       11. An image forming apparatus comprising:
 a light source; and 
 an optical scanner according to  claim 6 . 
 
     
     
       12. The optical scanner according to  claim 1 , wherein the non-deformable sections, the drive section-side shaft sections, and the drive sections are thicker than the movable plate-side shaft sections, the pairs of the deformation sections, and the pairs of the shaft sections. 
     
     
       13. An image forming apparatus comprising:
 a light source; and 
 an optical scanner according to  claim 12 . 
 
     
     
       14. The optical scanner according to  claim 1 , wherein each the drive sections is rectangular in an X-Y plane view. 
     
     
       15. An image forming apparatus comprising:
 a light source; and 
 an optical scanner according to  claim 14 . 
 
     
     
       16. The optical scanner according to  claim 1 , wherein each of the drive sections has first outer sides and second outer sides that are longer than the first outer sides in an X-Y plane view, and
 in each of the link sections, the drive section-side shaft section is connected to one of the second sides and the pair of shaft sections is connected to the first sides. 
 
     
     
       17. An image forming apparatus comprising:
 a light source; and 
 an optical scanner according to  claim 16 . 
 
     
     
       18. The optical scanner according to  claim 1 , wherein each of the non-deformable sections is positioned at a height greater than a height of each of the deformation sections in a thickness direction of the non-deformable sections. 
     
     
       19. An image forming apparatus comprising:
 a light source; and 
 an optical scanner according to  claim 18 .